This is a foolish question but does one have to use antifreeze mixture in the system or can you use plain deionized water. I am asking because I am considering buying this system but I have pets and if there is a leak I dont want poisen liquid spewing all over the floor.

Also for anyone that might own this system can you hear the pump or what kind of noise does it have when it runs. Hum or buzz ect. I know that spcr review says that its silent but silent is a very subjective term. Silent for the standard water setup or truely silent as you dont hear anything at all.

you don't need antifreeze for an air-cooled rad unless it's sitting outside through winter. distilled water should be fine; however, you'll probably still need/want something to prevent corrosion and possibly a surfactant (water wetter type stuff). not sure how toxic these sorts of things are, but at least they probably won't be delicious like antifreeze. surfactants are basically soap, i don't think most will cause anything worse than diarrhea.

i don't own a reserator myself and i don't know what it's made out of, but even with a 100% copper system, you'd still want an anticorrosive, perhaps even more so - pure DI water will literally dissolve copper after a relatively short while. it seems pretty sturdy though, and having the res, rad and pump all in one eliminates at least 4 points of failure; if you're careful with all your fittings i'd guess your pets would be more likely to get hurt by having it fall on them.

Thanks I appreciate the help. I am very excited about this product.